@article{NaithaniKlostermeyerLangeetal.1971,
  author    = {Naithani, V. K and Klostermeyer, Henning and Lange, H. R. and [u.a.], and Berndt, Heinz and [u.a.],},
  title     = {Preparation of peptide derivatives for porcine proinsulin-synthesis},
  series = {Biological Chemistry},
  volume    = {352},
  journal   = {Biological Chemistry},
  number    = {1},
  publisher = {De Gruyter},
  issn      = {1437-4315},
  doi       = {10.1515/bchm2.1971.352.1.1},
  pages     = {2 -- 3},
  year      = {1971},
  language  = {en}
}
@article{PawelkeButzer1968,
  author    = {Pawelke, Siegfried and Butzer, Paul L.},
  title     = {Semi-groups and resolvent operators},
  series = {Archive for Rational Mechanics and Analysis},
  volume    = {30},
  journal   = {Archive for Rational Mechanics and Analysis},
  number    = {2},
  publisher = {Springer},
  address   = {Berlin},
  issn      = {0003-9527},
  doi       = {10.1007/BF00250941},
  pages     = {127 -- 147},
  year      = {1968},
  language  = {en}
}